Safety Mode is an option that was introduced in Fable II which allows you to attack civilians. In Fable II, you obviously cannot kill villagers or small things like bunnies, but if you turn the Safety Mode off, they will glow red instead of purple and you can kill them. To turn Safety Mode off, you go to the expression wheel and go to the icon that has a white skull with a red line crossed over it. Activate it and any villager or living thing will glow red meaning that they are able to be killed. On the quick expressions list (which is the D-PAD for Xbox 360 for example), there is always the expression to turn Safety Mode back on by pressing the down button on the D-PAD. Killing villagers will result in giving you evil points, guards attacking you if you have multiple kills, and more people hating and fearing you. In Fable III, Safety Mode can be turned off by pressing down on the D-PAD while having a weapon drawn.

Notes

Safety Mode was mosy likely included due to the fact that it was easy to accidently kill or harm an innocent villager or guards in Fable and TLC.

In Fable II co-op, the host of the game world has control of the Safety Mode.

In Fable II, there is an achievement called The Hunter that is unlocked by killing a bunny with the Safety off.

In Fable III co-op, both players have control of their own Safety Mode.